STM32 第17章 EXIT--外部中断/事件控制器
时间：2024.10.23
参考资料：《零死角玩转STM32》“EXTI-外部中断/事件控制器”
STM32里每一个GPIO都能产生中断，中断的产生体现在GPIO的电平的变化，电平的变化需要一个外设来管理，最终传给NVIC(内核里的嵌套中断控制器)来处理。
一、学习内容
1、EXTI功能框图+EXTI初始化结构体
1.1EXTI简介
EXTI:
External interrupt/event controller,外部中断/事件控制器
管理控制器的20个中断/事件线。每个中断/事件线都对应一个边沿检测器，可以实现输入信号的上升沿或下降沿的检测。EXTI可以实现对每个中断/事件线进行单独配置，可以单独配置为中断或者事件，以及触发事件的属性。
EXTI两大功能：
产生中断；产生事件
1.2EXIT功能框图
1.2.1输入线
1.输入线总共有多少，具体是哪一些?
输入线一共20条（20个中断/事件输入线），这些输入线可以通过寄存器设置为任意一个GPIO，也可以是一些外设的事件。输入线一般是存在电平变化的信号。
EXTI0至EXTI15用于GPIO，通过编程控制可以实现任意一个GPIO作为EXTI的输入源。
EXTI19针对的是互联型的单片机，即105和107系列的，103系列的没有这个输入线。
2.通过配置哪个寄存器来选择?
参考手册-8.4.3-8.4.6外部中断配置寄存器1-4(AFIO_EXTICR1-4)
3.用函数如何选择具体的输入线?
stm32f10x_gpio.h里的对应功能的函数
void GPIO_EXTILineConfig(uint8_t GPIO_PortSource, uint8_t GPIO_PinSource);详细功能说明：
/**
* @brief Selects the GPIO pin used as EXTI Line.
* @param GPIO_PortSource: selects the GPIO port to be used as source for EXTI lines.
* This parameter can be GPIO_PortSourceGPIOx where x can be (A..G).
* @param GPIO_PinSource: specifies the EXTI line to be configured.
* This parameter can be GPIO_PinSourcex where x can be (0..15).
* @retval None
*/
void GPIO_EXTILineConfig(uint8_t GPIO_PortSource, uint8_t GPIO_PinSource)
{
uint32_t tmp = 0x00;
/* Check the parameters */
assert_param(IS_GPIO_EXTI_PORT_SOURCE(GPIO_PortSource));
assert_param(IS_GPIO_PIN_SOURCE(GPIO_PinSource));
tmp = ((uint32_t)0x0F) << (0x04 * (GPIO_PinSource & (uint8_t)0x03));
AFIO->EXTICR[GPIO_PinSource >> 0x02] &= ~tmp;
AFIO->EXTICR[GPIO_PinSource >> 0x02] |= (((uint32_t)GPIO_PortSource) << (0x04 * (GPIO_PinSource & (uint8_t)0x03)));
}
1.2.2EXTI初始化结构体EXTI_InitTypeDef
1.EXTI_Line：用于产生中断/事件线
2.EXTI_Mode:EXTI模式(中断/事件）
3.EXTI_Trigger:触发(上/下/上下）
4.EXTI_LineCmd:使能或者失能(IMR/EMR）
在stm32f10x_exti.h里找到结构体
/**
* @brief EXTI Init Structure definition
*/
typedef struct
{
uint32_t EXTI_Line; /*!< Specifies the EXTI lines to be enabled or disabled.
This parameter can be any combination of @ref EXTI_Lines */
EXTIMode_TypeDef EXTI_Mode; /*!< Specifies the mode for the EXTI lines.
This parameter can be a value of @ref EXTIMode_TypeDef */
EXTITrigger_TypeDef EXTI_Trigger; /*!< Specifies the trigger signal active edge for the EXTI lines.
This parameter can be a value of @ref EXTIMode_TypeDef */
FunctionalState EXTI_LineCmd; /*!< Specifies the new state of the selected EXTI lines.
This parameter can be set either to ENABLE or DISABLE */
}EXTI_InitTypeDef;
1.EXTI_Line：用于产生中断/事件线
/** @defgroup EXTI_Exported_Constants
* @{
*/
/** @defgroup EXTI_Lines
* @{
*/
#define EXTI_Line0 ((uint32_t)0x00001) /*!< External interrupt line 0 */
#define EXTI_Line1 ((uint32_t)0x00002) /*!< External interrupt line 1 */
#define EXTI_Line2 ((uint32_t)0x00004) /*!< External interrupt line 2 */
#define EXTI_Line3 ((uint32_t)0x00008) /*!< External interrupt line 3 */
#define EXTI_Line4 ((uint32_t)0x00010) /*!< External interrupt line 4 */
#define EXTI_Line5 ((uint32_t)0x00020) /*!< External interrupt line 5 */
#define EXTI_Line6 ((uint32_t)0x00040) /*!< External interrupt line 6 */
#define EXTI_Line7 ((uint32_t)0x00080) /*!< External interrupt line 7 */
#define EXTI_Line8 ((uint32_t)0x00100) /*!< External interrupt line 8 */
#define EXTI_Line9 ((uint32_t)0x00200) /*!< External interrupt line 9 */
#define EXTI_Line10 ((uint32_t)0x00400) /*!< External interrupt line 10 */
#define EXTI_Line11 ((uint32_t)0x00800) /*!< External interrupt line 11 */
#define EXTI_Line12 ((uint32_t)0x01000) /*!< External interrupt line 12 */
#define EXTI_Line13 ((uint32_t)0x02000) /*!< External interrupt line 13 */
#define EXTI_Line14 ((uint32_t)0x04000) /*!< External interrupt line 14 */
#define EXTI_Line15 ((uint32_t)0x08000) /*!< External interrupt line 15 */
#define EXTI_Line16 ((uint32_t)0x10000) /*!< External interrupt line 16 Connected to the PVD Output */
#define EXTI_Line17 ((uint32_t)0x20000) /*!< External interrupt line 17 Connected to the RTC Alarm event */
#define EXTI_Line18 ((uint32_t)0x40000) /*!< External interrupt line 18 Connected to the USB Device/USB OTG FS
Wakeup from suspend event */
#define EXTI_Line19 ((uint32_t)0x80000) /*!< External interrupt line 19 Connected to the Ethernet Wakeup event */
#define IS_EXTI_LINE(LINE) ((((LINE) & (uint32_t)0xFFF00000) == 0x00) && ((LINE) != (uint16_t)0x00))
#define IS_GET_EXTI_LINE(LINE) (((LINE) == EXTI_Line0) || ((LINE) == EXTI_Line1) || \
((LINE) == EXTI_Line2) || ((LINE) == EXTI_Line3) || \
((LINE) == EXTI_Line4) || ((LINE) == EXTI_Line5) || \
((LINE) == EXTI_Line6) || ((LINE) == EXTI_Line7) || \
((LINE) == EXTI_Line8) || ((LINE) == EXTI_Line9) || \
((LINE) == EXTI_Line10) || ((LINE) == EXTI_Line11) || \
((LINE) == EXTI_Line12) || ((LINE) == EXTI_Line13) || \
((LINE) == EXTI_Line14) || ((LINE) == EXTI_Line15) || \
((LINE) == EXTI_Line16) || ((LINE) == EXTI_Line17) || \
((LINE) == EXTI_Line18) || ((LINE) == EXTI_Line19))
/**
* @}
*/
/**
* @}
*/
/** @defgroup EXTI_Exported_Macros
* @{
*/
/**
* @}
*/ EXTI_Line初始化对应的是向下图的哪个位写1，而不是选择总线
2.EXTI_Mode:EXTI模式(中断/事件）
/**
* @brief EXTI mode enumeration
*/
typedef enum
{
EXTI_Mode_Interrupt = 0x00,
EXTI_Mode_Event = 0x04
}EXTIMode_TypeDef;
#define IS_EXTI_MODE(MODE) (((MODE) == EXTI_Mode_Interrupt) || ((MODE) == EXTI_Mode_Event))3.EXTI_Trigger:触发(上/下/上下）
/**
* @brief EXTI Trigger enumeration
*/
typedef enum
{
EXTI_Trigger_Rising = 0x08,
EXTI_Trigger_Falling = 0x0C,
EXTI_Trigger_Rising_Falling = 0x10
}EXTITrigger_TypeDef;
#define IS_EXTI_TRIGGER(TRIGGER) (((TRIGGER) == EXTI_Trigger_Rising) || \
((TRIGGER) == EXTI_Trigger_Falling) || \
((TRIGGER) == EXTI_Trigger_Rising_Falling))4.EXTI_LineCmd:使能或者失能(IMR/EMR）
2、GPIO外部中断代码
2.1 实验设计
1. PA0连接到EXTI用于产生中断，PA0的电平变化通过按键来控制
2产生一次中断，LED反转一次